Valve construction



Patented July 8, 1924.

MILTON'H. SMITH, 0F DETROIT, MICHIGAN.

vALvE CONSTRUCTION.

Apnlication led 0ctober'29, 1923., Serial N0. 671,852.

To all whom it may concern: 3

- Be it known'that I, MILTON H. SMITH, a citizen of the United States, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in 'Valve Constructions, of which the following is a specilication.

This invention relates to valvesV and valve gear and especially valves intended for in- -ternal combustion engines.. One of the greatest difficulties. hexperienced in the smooth running of automobile engines is valve noise.- This is more, pronounced vin the overhead type of valve than in the L or T head motor. In the overhead'type of valve the noise is due to the largeamount of exposed valve gear and the several points of clearance. It is also due in the both forms of motors toside thrust of the cams or rocker arms which communicate the movement to the tappets or push rods. This very` often results in considerable Wear in the valve 'stem guide or the tappet guide, resulting lin looseness which furnishes a large amount of clicking and noise the operation of the motor.

In my improved valve and valve gear construction, this is largelyv obviated. There is a further improvemennt in -that `-the thrust member may be changed to alter the lift of the valve without inany way changing the lengthof the valve stem or without .changing the cams.

This will be more full explained hereinafter.

In the drawings:

F 1 is a vertical crosssectionthrough an internal combustion' engine provided with overhead cam shafts and overhead valves. K

Fig. 2 is a section taken on the line 2-2 of Fig. 1. A

Fig. 3 is a detail in perspective of one of the thrust blocks. Y i

Fig. 4 is a detail showing a thrust block having a different -inclination of its surfaces. v

No extended description of the various partsof the motor need .be given; it will be apparent from the drawings `the motor has the usual spark plug, piston, water cooling i -spaces, exhaust and intake, etc. A pair of overhead cam shafts a and b are enclosed in the extension of the engine casting, which forms the lower half c of the valve housing. Theupper half of the valve housing is se- -pet and push rod cured to the lower half and comprises a removable cover d. The valve isv designated e, and the valve stem f. The end of this stem is threaded as at g, and on this screws the acorn nut h provided with a ball ter# minal z', over which loosely fits the thrust block k. This acorn nut may be locked in any adjustedhposition by means of the lock nut n designates the valve stem guideI which in 'the A,ordinary lconstruction very often Wears due to the side thrust` Com pression springs o and p engage against the removable washer 1' to normally'set the valve onthe valve seat.4 l I In place of the ordinaryrocker arm, tapear used on Athe top of ther motor, I provide a valve gear housing formed b. anyextension of the engine cast- .ing that forms the lower half, and the removable cover member d that forms the upper half. Within this valve housing two overhead cam shafts are driven 'at equal speed in opposite directions. The thrust block c, of triangula1-cross section,

placed loosely on the top of the ball terminal-2'. It is provided with a ball socket iri which sets thebalL Thetwo cam elevations are adapted to simultaneously ride down the slopes of this roof-like thrust member. The consequence is that thel side thrust of one cam is neutralized -by the side thrust of the other cam, and all the resultant thrust is in a'straight line axially of the valve stem. This avoids all sidel thrust which Aoften results in noise for it wears the valve guidel and affords the'objectionable clicking, as observed in so many otherwise smooth running motors.

Another very important factor in-this im- .pnoved constructionresides inthe interchangeability of the thrustblocks. By using such a thrust block as shown in Fig. 4, the lift of the valve may be lessened.v If a greaterv lift vof the valve'is desired, then a thrust .block' of a less acute angle may be used. This will change the circumferential travel of the two cams to a larger longitudinal movement of the valve stem. This makes it .very easy to Achange the opening of the valve without in any way altering the cam shaft. It is a very diicult thing to lay out f and build a proper master cam shaft.' Inmy construction, the manufac- 'turen may easily alter the lift of his valveby simply changing the inclination on th'e thrust blocks.

urthermore, a variety of thethrust blocks offers an optional valve lift for the'user of the car,

The construction that I` have illustrated vis not peculiar to overheadtcam shafts. It

will be obvious that the double op'positel running cams could be used equally wel where the cams are located below the combustion chamber, and the motor is eitheran L head or T head type.

I have used the term push member in 1. In a valve mechanism, the combination y "of a longitudinally guided valve and push member, and two separate actuating members 'engaging at opposite sides of the valve stem forv thrusting the valve open, said members serving to neutralize the side thrust von the push member.

2. In a valve mechamsm, the combination of a longitudinallyguided valve and push member, a pair" 'of oppositely rotating ca'ms 'for thrusting the valve open and so located as' to neutralize side thrust on the push member.

3. In a valve mechanism, the combination of a longitudinally guided valve andl push member, and a pair of directly opposed ro-y tating cams located on opposite sides atthe end yof the '.push member for thrusting the valve and push member, and neutralizing side thrust on the push member.

4. In a valve mechanism, a longitudinally guided valve and push member, a rockable thrust member on the end of the said member, and a pair of actuating members engaging the thrust members on opposite sides of the axis of the push member for opening the valve and neutralizing side thrust on the push member.

5. In a valve mechanism, the combination of a longitudinally guided valve and push member, a rockable thrust member located on the end of the push member,-and a pair of oppositely rotating cams adapted to engage at opposite sides ofthe thrust member Jfor thrusting the valve open and neutralizing the side thrust.

6. vIn a valve mechanism, a longitudinally guided valve and` push member provided with a ball terminal, a rockable thrust member supported on the ball'terminal, and a pair of actuating members located on opposite sides of the axis of the push member member to open the valve.

7 In a valve mechanism, a longitudinally guided valve and push member, an adjustable acorn nut secured on the end of the push member and provided with a ball terminal, a thrust member rockably supported on said acorn nut, a pair of actuating mem-A bers contacting oppositel sides of the thrust member and engaging on Opposite sides of the axis of the push member for opening the valve. Y

8. In a valve mechanism, a longitudinally guided valve and .push member, a thrust member provided with two oppositely inclined sides and engaging the end of the push member, and a pair of oppositely positioned, oppositely rotating'cams engaging 'for engaging opposite sides of the thrust i the two 'inclined sides ofthe thrust inember.

9. In a valve'mechahism, a longitudinally guided valve and push member provided with a ball terminal, a thrust member loosely fitting over the ball terminal and provided with oppositely-inclined sides, and a pair of oppositely positioned and oppositely rotating cams for engaging the two inclinedA sides of the thrust member for opening the valve.

10. In a valve mechanism, the combination .of a longitudinally guided valve and push member', a-lremovable thrust member supported on -the'end of the push member' by which the inclination of thesides of the thrust member may be altered by interchanging the individual thrust member, and a pair of actuating members forcentacting the inclined sides of the thrust member, and which serve toA lift the valve a vary ing distance depending upon the inclination esl of the sides of the individual thrust member used.

In .testimony whereof he has ahxed his MILTONV H. SMITH.

signature. 

